The Instrument Development Core for the "Network for Translational Research in Optical Imaging" will overview the center hardware development and standardization. The major goal of this Core is to design a common instrument platform for the clinical components of the network. This common platform will be based on frequency-domain techniques. The instrument design will allow standardization of the measurement protocol. Specific instrument features will allow comparison of sensitivity and accuracy in the determination of the optical parameters and will generate data that will interface with the Software Core. Of particular importance is the design of the scanner, which will generate images that can be overlaid and compared with other imaging modalities such as x-ray mammography, MRI, and ultrasound. This Instrument Development Core will closely interact with the Clinical Cores and will provide them with standardized instrumentation. The Instrument Development Core will also interact with manufacturers of the various hardware components needed for the instrumentation and will provide them with specifications and timetables. The Instrument Development Core is centered on two major research groups at the University of Illinois and at the University of Pennsylvania. In recent years, these two groups have been at the forefront of instrument development based on the frequency-domain approach. Partnerships with local manufacturers and local expertise have been established for the rapid commissioning of the insmmaentation. The Insmnnent Development Core will interact with the Core Projects 1, 2, and 3 and will work in close relationship with the industrial manufactures participating in this Consortium. An Advisory Committee will overview the operations of the Instrument Development Core.